Help me understand this problem. I build up my new machine, all ready to fire up but:

- when I turn it on all fans (cooler, psu, system fans) spin for a 1-2 seconds then turn off;- then he keeps on doing it endlessly until I unplug it.

What can it be?

The motherboard (GIGABYTE B75M-D3H) has 2 x 4-pin ATX 12V power connector but my PSU only has 4-pin ATX 12V,the board has 24-pin ATX main power connector and the PSU is 20+4 pin. Is this why it doesn't work?

The 4-pin vs. 8-pin ATX 12V combination isn't necessarily problematic, but could be if you've got a power-hungry CPU. I suppose there may be mobos that require the 8-pin connection even with lower-powered CPUs, but I haven't seen one.

The 20+4 vs. 24 pin thing is normal. PSU vendors do this to maintain backward compatibility with older motherboards that have a 20-pin main connector.

EDIT

Just saw your PSU specs; depending on what else is in this system that could be underpowered. Please post the rest of your system specs.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

If you recently bought the PSU, you should be able to return it and change it with another model that has all the right cable connectors. Personally i've heard that a 4pin cpu connector should work fine on a mobo with 8 pin CPU header, if the psu is strong enough compared to the power consumption.

If you say that it doesn't work, then you probably need a beefier PSU. Btw, what are the other spex of the PC?

nVidia video drivers FAIL, click for more infoDisclaimer: All answers and suggestions are provided by an enthusiastic amateur and are therefore without warranty either explicit or implicit. Basically you use my suggestions at your own risk.

Double-check that you haven't accidentally grounded something to the case (with an extra motherboard standoff, for example).Simplify the trouble-shooting by unplugging most components and starting with just the PSU, motherboard, CPU and RAM. Then gradually plug in fans, hard-drives, etc.

JustAnEngineer wrote:Double-check that you haven't accidentally grounded something to the case (with an extra motherboard standoff, for example).Simplify the trouble-shooting by unplugging most components and starting with just the PSU, motherboard, CPU and RAM. Then gradually plug in fans, hard-drives, etc.

Sir, are you saying for example, plug of all things except the CPU and see if it starts, then add the RAM and see if it starts, then HDD's etc?

At this point we can speculate that's it's either the fault of the PSU or the motherboard. You could at the very least test with another PSU from a friend or a local IT shop to confirm or deny if it's the PSU.

If you test with a PSU that is known to work and yet the system will exhibit the same behaviour then it's most likely the mobo''s fault.

Edit:I see in your signiture that you also have a Earthwatts 500W? Try using that for the test....

nVidia video drivers FAIL, click for more infoDisclaimer: All answers and suggestions are provided by an enthusiastic amateur and are therefore without warranty either explicit or implicit. Basically you use my suggestions at your own risk.

Arclight wrote:At this point we can speculate that's it's either the fault of the PSU or the motherboard. You could at the very least test with another PSU from a friend or a local IT shop to confirm or deny if it's the PSU.

If you test with a PSU that is known to work and yet the system will exhibit the same behaviour then it's most likely the mobo''s fault.

Edit:I see in your signiture that you also have a Earthwatts 500W? Try using that for the test....

Indeed I have, although I would be easier to go to the shop for the test is close to my home

vargis14 wrote:2 560 tis in sli can pull well over 300 watts loaded. Pull one card out remove the motherboards battery, reset cmos and recheck all connections and make sure ram and cards are properly seated.

Jon1984 wrote:I recall now, I didn't install the system speaker... Could this be a issue also? I'll install it when I get home so maybe the "beeps" will tell me something more about the problem also.

I personally had problems with a new DOA mobo that exhibited the issues as yours, but there are others who described simillar symptomps but the cause was different ranging from defective PSU to discrete video card.

Since your system only quirk seems to be the PSU and the video output comes from the IGP, naturally i suspect the PSU or the motherboard. That said we aren't magicians, unless you start actually testing parts yourself we can't do anything. It's clear that you have enough knowledge with DIY builds, i doubt the mobo speaker would help. It usuually does if the mobo works and we haven't established that yet. Maybe i'm crazy but i sense a touch of sarcasm in your tone.

Is this thread even for a real system? I'm having doubts right now due to your responses.

nVidia video drivers FAIL, click for more infoDisclaimer: All answers and suggestions are provided by an enthusiastic amateur and are therefore without warranty either explicit or implicit. Basically you use my suggestions at your own risk.

It could be something as simple as a cable plugged into the wrong slot. I recently got more memory and in order to install it I disconnected the cables that went to the front of my board (HD/Power/Reset/Speaker). When I reconnected them and tried to power up the computer I got into a similar situation where I could see the fans spin up for a few seconds, stop and then restart about ten seconds later. It kept doing that forever. It turns out that when reconnecting the cables I had put some in the wrong spot. (Easy to do since they were all together and had no keying to prevent you from making a mistake.)

It took me a few minutes to figure out what was causing the problem but once I reconnected the wires in the proper order everything worked great and the system booted up as it should.

Jon1984 wrote:I recall now, I didn't install the system speaker... Could this be a issue also? I'll install it when I get home so maybe the "beeps" will tell me something more about the problem also.

I personally had problems with a new DOA mobo that exhibited the issues as yours, but there are others who described simillar symptomps but the cause was different ranging from defective PSU to discrete video card.

Since your system only quirk seems to be the PSU and the video output comes from the IGP, naturally i suspect the PSU or the motherboard. That said we aren't magicians, unless you start actually testing parts yourself we can't do anything. It's clear that you have enough knowledge with DIY builds, i doubt the mobo speaker would help. It usuually does if the mobo works and we haven't established that yet. Maybe i'm crazy but i sense a touch of sarcasm in your tone.

Is this thread even for a real system? I'm having doubts right now due to your responses.

Sorry if I'm not sounding correctly. I asked about the system speaker because when I turn on the PC there are no "beep" sounds, if I recall normally when something isn't correctly placed or missing, the beeps allow you to understand the problem at hand.

Yes it is a real system of course, I'm not trying to waste all your time

nanoflower wrote:It could be something as simple as a cable plugged into the wrong slot. I recently got more memory and in order to install it I disconnected the cables that went to the front of my board (HD/Power/Reset/Speaker). When I reconnected them and tried to power up the computer I got into a similar situation where I could see the fans spin up for a few seconds, stop and then restart about ten seconds later. It kept doing that forever. It turns out that when reconnecting the cables I had put some in the wrong spot. (Easy to do since they were all together and had no keying to prevent you from making a mistake.)

It took me a few minutes to figure out what was causing the problem but once I reconnected the wires in the proper order everything worked great and the system booted up as it should.

Yes, I'm not fully confident if those connections were made correct, I will try to make a research about those connections and see if the problem could be on those

Jon1984 wrote:Sorry if I'm not sounding correctly. I asked about the system speaker because when I turn on the PC there are no "beep" sounds, if I recall normally when something isn't correctly placed or missing, the beeps allow you to understand the problem at hand

Jon1984 wrote:Sorry if I'm not sounding correctly. I asked about the system speaker because when I turn on the PC there are no "beep" sounds, if I recall normally when something isn't correctly placed or missing, the beeps allow you to understand the problem at hand

Does your case even have the speaker? Not many do these days.

It as something called "Buzzer" that connects to the MB somewhere I guess... Not sure... Maybe only on older boards have a connection for this.

Jon1984 wrote:It as something called "Buzzer" that connects to the MB somewhere I guess... Not sure... Maybe only on older boards have a connection for this.

The boards still have the connection, it's just that most modern cases don't have the speaker in them.

EDIT: Grabbed the manual for your case and it does come with a buzzer unit. The manual for your motherboard shows speaker pins on the F_PANEL header in the bottom right corner of the board (as oriented in the case). Unfortunately, the manual for your motherboard doesn't list beep codes.

Even if it is correctly placed, there could be an extra standoff underneath that does not correspond to a motherboard mounting hole.

Jon1984 wrote:I recall now, I didn't install the system speaker... Could this be a issue also? I'll install it when I get home so maybe the "beeps" will tell me something more about the problem also.

Not connecting a speaker won't cause problems. In some cases the beeps can help you diagnose the problem, but it sounds like the system is powering down before it would have a chance to give you any beep codes.

vargis14 wrote:2 560 tis in sli can pull well over 300 watts loaded.

Where did he say he had a pair of 560 Tis?

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson